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SHOP PROBLEMS 



IN 



SHEET METAL 



EUGENE C. GRAHAM 



EVANSVILLE, INDIANA 
1918 



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SHOP PROBLEMS 

IN SHEET METAL 

FOR SECONDARY SCHOOLS 

WITH NOTES ON EQUIPMENT, MATERIALS 
AND SHOP METHODS 

By 
EUGENE C. GRAHAM 

Director Vocational Education 
Evansville, Indiana 



PRINTED ON THE HIGH SCHOOL PRESS 

EVANSVILLE, INDIANA 

1918 



60C3000C 



3< >OOOC30C 



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COPYRIGHT, 1918, 
EUGENE C. GRAHAM 



0QU483887 



JUL 23 1318 



Q Shop Problems in Sheet Metal 



THE TRADE OF THE SHEET METAL WORKER. 

As an introduction to this little collection of notes and drawings the author 
wishes to call the attention of High School boys especially to the fact that this 
trade has not received the attention it deserves from the schools. In recent years 
several vocations such as printing, concrete construction, automobile repair and 
electrical work have found a place in the schools while others seem to be losing 
ground. It seems to be true that trades such as blacksmithing and molding 
which have been influenced by the introduction of new machinery which is more 
or less automatic, have become less attractive to boys. 

Sheet metal work as a vocation has many attractive features. It is a large 
and growing industry represented both in the building trades and in modern 
automobile construction, furniture and boat building and in the construction 
of manufactured articles. The introduction of autogenous welding and electric 
welding has done much to make possible the use of sheet metal in new forms. 

All well trained sheet metal workers can draft their own patterns. Boys 
who have been unable to see any use for intersections and developments in 
mchanical drawing can quickly see the relation between this branch of drawing 
and the drafting of patterns. 

The working of metal in sheet form is light, interesting and instructive. The 
making of kitchen utensils, such as pans, sugar scoops, funnels, dustpans, can- 
teens, bread boxes and other articles is attractive to most boys. A large num- 
ber of hand operated machines are used and the training afforded by these ma- 
chines is valuable. Boys like wood turning because they can run the machines 
for themselves. In the same way they become interested in the machines used 
to bend and shape sheet metal and can make a larger variety of useful products 
than in nearly any other school shop. 

Boys who are interested in the trade will find that the wages paid are better 
than in some other related trades and that there is always a demand for com- 
petent men. 

The author hopes to add to this collection of drawings from time to time 
and will welcome suggestions and criticisms. The notes are merely a bare out- 
line of related facts and should be supplemented by outside reading and visits 
to shops where sheet metal is used. 

Credit is due the Peck, Stow and Wilcox Co., of Southington, Conn., for 
the electrotypes used. The list of equipment is from their "Pexto" line, which 
has been used with satisfaction by many schools. 



Page One 



Shop Problems in Sheet Metal 



MATERIALS USED BY THE SHEET METAL WORKER. 
Articles made of sheet metal are commonly made either of tin plate, sheet 
iron or galvanized iron. Other kinds of sheet metal sometimes used are sheet 
copper, sheet aluminum, sheet zinc or sheet brass. Each of these materials has 
some special advantages but it may be said that if we could neglect the item of 
first cost either sheet copper or sheet aluminum would take the place of most of 
the other materials. A short paragraph on the qualities of each of the above ma- 
terials is given below. 

Tin Plate. 

It is often a surprise to a pupil to find that even good tin plate is not made 
of pure tin. Since it is covered with a metal so different from iron in appear- 
ance it is not easily discovered that it is made of sheets of iron covered on both 
sides with a coating of tin. The thickness of this coating varies somewhat with 
the quality but it is never very thick, It is put on by dipping plates of iron 
which have been carefully cleaned in acid and scrubbed with sand and water, 
into tanks of melted tin. The tin forms a kind of an alloy with the iron in the 
plate and after passing through the bath of tin one or more times and being 
carefully cleaned and inspected it becomes a sheet of tin plate. Sometimes lead 
is mixed with the tin anc 1 with this change "terne" plates are made for roofing 
buildings. 

Tin plate is easily worked, is not easily affected by air or water, takes sol- 
der well and can be kept bright and clean without much trouble. It is the cheap- 
est material used for kitchen ware. 

Sheets of tin are usually 20x28 inches in size, but they may be had half that 
size or 14x20 inches and several other sizes are made. In thickness they run 
from 20 wire gauge to 30 and they may have from one to three coats of tin. 
Articles made of tin plate are often retinned after manufacture. This cannot be 
done with soldered work. Why? 

Sheet Iron. 

Plates of soft sheet iron are used for roasting pans, stove pipe and as a lin- 
ing for ovens. When of nearly pure iron and treated with a process to prevent 
rust it becomes a good material for limited uses. It cannot be soldered and is 
easily affected by water and acids. 

Galvanized Iron. 

Galvanized iron is sheet iron or steel coated with zinc, somewhat as tin 
plate is coated with tin. The zinc coating makes it rust proof for a long time 
and gives it a pleasing appearance. However the zinc will not stand acids and 
is likely to peel off in flakes if the metal is hammered or bent. It does not polish 
well but can be kept clean by washing. It is not used in making kitchen ware 
but for dry measures, roofing, etc it is in common use. 

Galvanized sheets are usually 30 inches wide and 96 inches long. Wider and 
longer sheets may be bought. The thickness runs from 16 wire gauge or thicker 
down to 30 wire gauge. Galvanized sheets from 24 to 30 gauge are most com- 
monly used in schools. 

Page Two 



Shop Problems in Sheet Metal 



Sheet Copper. 

This metal comes in sheets nearly pure and can be had in many thicknesses 
and sizes. When used by the sheet metal worker it has many fine qualities and 
can be drawn, hammered, soldered, and pressed into many shapes. It is tough 
and stands working better than most metals. It can be annealed or made soft 
by heating and quenching in water. When made into utensils it is usually tinned 
and often nickel plated on the outside of the vessel. Pure copper is somewhat 
acted on by the air and by water and more by acids, so that tinning is neces- 
sary for some-purposes. On account of the cost it is not much used, but is a 
very durable roofing material. Copper is used for many articles which are beat- 
en into shape by hammering. 

Sheet Zinc. 

This metal has many valuable qualities and is used for roofing, tops for 
kitchen cabinets, ornamental vases, etc. It is very little acted on by the air after 
the first film of oxide forms on the surface. It may be soldered if care is taken 
to avoid burning through the metal with a copper which is too hot. Dilute mu- 
riatic acid is used as a flux in soldering zinc. 

Sheet Brass. 

Sheet brass has many of the qualities of copper. It is somewhat harder and 
requires more care in bending. By annealing it carefully it may be worked into 
many shapes. Borax may be used as a flux in soldering brass. Because of the 
increased cost it is not much used except in some manufactured articles such as 
automobile lamps. 

Sheet Aluminum. 

This metal is coming into very general use for kitchen utensils. It is very 
durable and easily kept clean. It is not much acted on by the air or by water 
and acids, but alkalies have some affect on it. Since its melting point is much 
lower than that of copper and iron it may be melted through on a hot range if 
the vessel boils dry. It is very easily worked and may be pressed and drawn 
into various shapes. Since it cannot be soldered with much success it must 
either be welded or riveted. Many articles are cast into shape. Aluminum rivets 
should be used for fastening handles and other attached parts. 



Page Three 



Shop Problems in Sheet Metal 



MACHINES USED IN SHEET METAL WORK. 

In the following paragraphs simple instructions are given in the use of the 
machines most commonly found in school shops. Nearly all of these machines 
are easily understood by boys and with these directions before them most pu- 
pils can quickly acquire considerable skill. At first it will be necessary for the 
instructor to make most of the adjustments but pupils should be required to 
learn to make the more common adjustments themselves. One of the rules of 
the shop should be that each pupil should look into the adjustments of a ma- 
chine every time he uses it. If he is not sure he should ask the instructor to 
test the adjustment for him. 

The Squaring Shears. 

All stock for articles made of sheet metal must first be cut from the orig- 
inal sheets. The machine used for this work is called the squaring shear. It 
may also be used for much straight cutting in trimming stock to exact sizes. 
The cut is made in straight lines only and the machine has guides and guages 
to be used in squaring and cutting to the required widths and lengths. Usual- 
ly the work is inserted from the front of the machine but long sheets may be 
worked from either front or back. The side guides should always be used in 
squaring work. Care must always be taken to keep fingers from under the 
blade. No material thicker than twenty guage can be cut and hardened steel 
sheets of any thickness must not be cut. The work should be held down firmly 
on the bed of the machine while cutting. It will be advisable not to depend on 
the scale marked on the bed for accurate work. A steel rule should be used to 
check the setting. Keep the blades well oiled. 

The Forming Machine. 

This machine is a set of rolls for bending sheet metal or wire to a curved 
form. All articles made in the shape of a cylinder and others which are to be 
bent to a radius greater than one inch can be quickly formed in this machine. 

The machine consists of two geared rolls and one loose roll which serves to 
bend the work which passes between the first two. The distance between the 
geared rolls can be regulated by thumb screws. The rear roll can be raised to 
bend the sheet to a smaller radius. 

When operating the machine the beginner should raise the bending roll a 
little at a time until the proper curvature is produced. Both ends of this roll 
must be raised when adjusting the machine. 

When one edge of the work has been wired in the flat this wired edge should 
be run in one of the grooves turned in the rolls for this purpose. These grooves 
may also be used to form wire. 

You must always remember that the inside of the curve will always be on 
the surface nearest to the top roll. 



Page Four 



Shop Problems in Sheet Metal 



The Folding Machine. 

In order to turn a hem or lock on the edge of a piece of sheet metal some 
means must be found of holding the metal firmly while the edge is being turned. 
Or we may grip the edge and turn the fold by moving the piece itself. The or- 
dinary folder does the latter. Other machines are used called open throat fold- 
ers which use the former method. 

These machines will also prepare the edge of sheet metal to receive a wire 
All folders have adjustments to regulate the width of the fold and also the 
sharpness of bend, so that they may slso be used to prepare the edge of sheets to 
receive a wire. It is always necessary to know just how the machine is adjusted 
before attempting to make a fold or to wire an edge. 

The Grooving Machine. 

After a lock seam has been folded on the folder it should be closed down 
with a grooved wheel on the grooving machine. Hand tools are also used for 
this but in all cases where it is possible to use the machine it is better to do so. 
The grooving rolls are made to fit several widths of seam and the proper roll 
should be used. 

The Brake. 

This machine, commonly called the cornice brake, has a wider range of use- 
fulness than the folder. It may be used to turn hems or folds and also to make 
bends at all angles up to nearly 180 degrees, and at any distance from the edge. 
The brake also has attachments for forming molded shapes to almost any pat- 
tern. Lengths up to eight feet are in common use. 

In using this machine it is necessary to plan the bends to be made if sev- 
eral are to be turned in the same piece. Otherwise the pupil will find it hard to 
decide what the order of operations should be. 

It is advisable to mark the location of lines and bends with punch marks. A 
line may thus be transferred to the other side of the sheet accurately. 

Foot levers are provided to hold the work temporarily, but it is quite impor- 
tant that the cam levers should be used to clamp the work in place. Pupils 
should never attempt to bend heavy metal or wire in this machine. 

The Wiring Machine. 

After the use of the turning machine the wire is fitted to its place and part- 
ly closed in with a mallet. Then the wiring machine is used to tuck in the edge 
of the metal neatly around the wire. Some judgment is needed to set the ma- 
chine for different sizes of wire. 

This machine may also be used to wire the edges of flat work. Pains should 
be taken to keep the surface of the flat work horizontal or to raise the 
outer edge a little in order to prevent a ridge being formed on the lower side 
of the work. 

Page Five 



Shop Problems in Sheet Metal 



The Turning Machine. 

Turning machines are used to prepare the edge of a can body or other simi- 
lar work such as the edge of a funnel to receive a wire, When such work is 
ready it is placed on the lower grooved roll and against the guage. The screw 
is turned until the upper roll forms a slight groove in the work. After one revo- 
lution the work is tilted upward a little and the screw tightened until a deeper 
groove is formed. By repeating this operation and making several revolutions 
of the work the edge is prepared to receive the wire. To avoid some of the most 
common faults of beginners, try to turn slowly at first and to press the work 
firmly against the guage. After tilting the work upward do not allow it to drop 
back again. Do not force the rolls against the metal. Practice on some can 
bodies which have been cut down from discarded tomato cans to a height of 
about three inches. Serviceable tin cups may be made of these by wiring the 
top edge and soldering on a neat handle. Skill will come with practice. 

The Burring Machine. 

This machine is used for turning an edge on cylinders of metal or on discs 
such as can bottoms. In preparing vessels for double seaming a burr is first 
turned at a right angle on the body and then one of the same width on the edge 
of the bottom. This last operation is quite difficult and takes considerable 
practice. Bottoms can be made much better on a circular shear with a flanging 
attachment. 

In using the burring machine remember that only a narrow burr about one- 
eighth of an inch wide can be turned. The burring machine is the hardest ma- 
chine for beginners to use. The pupil should avoid spoiling good material un- 
til he has had careful instruction. 

The Setting Down Machine. 

This is used to close the seams left by the burring machine. It is very sim- 
ple and may be turned in either direction. It has no adjustments except for 
thickness of material. 



Page Six 



Shop Problems in Sheet Metal 



NOTES ON SOME OF THE MORE COMMON METALS AND ALLOYS 

Iron is a very common metal. It is found in many countries and especially 
in the United States. The mines near lake Superior on what is called the Iron 
Range, and other mines near Birmingham, Alabama, produce great quantities 
of iron ore. These ores are melted with lime stone, coal and coke in blast fur- 
naces which are about eighty feet high and twenty feet in diameter inside. These 
furnaces must be kept going night and day. The melted iron is cast into ingots 
called "pigs", or it may be made into steel in a Bessemer converter. Wrought 
iron is made from cast iron by removing impurities. Cast iron contains carbon, 
sulphur, silicon, phosphorus and other elements in varying proportions. These 
impurities make the cast iron brittle and weak as compared with steel and 
wrought iron. 

Steel contains elements like carbon, manganese, nickel, etc., in quite definite 
proportions and by varying these proportions the manufacturer can produce 
steel fit for steel beams, razor blades or watch springs and a hundred other 
products, as he chooses. 

Iron 

Iron is a silvery metal with a density of 7.86, a melting point of 2754 degrees 
and a weight per cubic foot of 480 lbs. 

It is ductile and malleable and almost as soft as aluminum. In the industries 
pure iron is seldom used. What is called mild steel is commonly used in its 
place. 

Copper 

Metallic copper has been known from the earliest times and was probably 
one of the first metals in use. It is a heavy metal of a reddish color with a 
density of about 8.93. It melts at 1948 degrees and weighs 552 lbs. per cubic 
foot. It is rather soft and is very ductile, malleable and flexible, yet tough and 
fairly strong. It is a very good conductor of heat and electricity. Copper is used 
for making alloys, for roofing, for electrical conductors and many other pur- 
poses. It can be rolled into sheets, hammered into shapes or drawn into wire. 

Lead 

Lead has been known from very early times. The Romans used it for water 
pipes, as we do now. It is a silvery metal of density 11.37, which melts at 588.6 
degrees. One cubic foot of lead weighs 710 lbs. While it is heavier than most 
metals there are some, such as gold and platinum, which are much heavier. It 
is very little affected by air or hard water and is used for pipes, for alloys and 
in many kinds of paint. Sheet lead is often used for lining tanks and lead plates 
are used in storage batteries. 

Tin 

Tin is a silver white metal harder than lead and quite malleable. It has a 
density about 7:29 and a melting point of 418.5 degrees. It weighs 458 pounds 
per cubic foot. Tin is used in the manufacture of alloys and as a coating for 
sheet steel to make tin plate. Pure tin is used as tinfoil, but compared with 
other metals it is not often used in this form. 

Page Seven 



Shop Problems in Sheet Metal 



Zinc 

Zinc is a bluish white metal. It has a density of 7.10 and a melting point of 
754.9 degrees. It weighs about 436 pounds per cubic foot. At some tempera- 
tures it is brittle but between 250 and 300 degrees it may be rolled into sheets 
and is then of great use as a sheet metal. Since it is cheaper than copper and 
lighter than lead it is used for roofs, gutters and architectural ornaments. Its 
chief uses are in the manufacture of alloys and in the coating of steel pipes and 
plates. This process is called galvanizing. The oxide of zinc is used in making 
paints, and zinc rods and bars are used in batteries. 

Aluminum 

Aluminum resembles tin in appearance. It has a density of only 2.65 and is 
therefore only about one-third as heavy as iron. One cubic foot weighs 166.5 
pounds. It melts at 1 185.3 degrees. It is ductile and malleable except at low and 
high temperatures. It is fairly hard and strong. Sheet and cast aluminum are 
used for cooking utensils. Aluminum wire is used for conductors. Aluminum- 
zinc alloys are used in castings for automobile parts. 

Alloys 

An alloy is a mixture or combination of two or more metals to obtain cer- 
tain desirable properties. These metals will in many cases unite in a great many 
different proportions, but to secure the desired properties only certain definite 
mixtures are commonly used. The advantages obtained are increases in strength, 
hardness, toughness or elasticity, a lower melting point or to facilitate the pro- 
duction of sound castings. 

Some of the more important alloys are as follows: 
Brass Made of Copper and zinc 

Aluminum bronze 
German Silver 
Manganese bronze 
Bronze 
Bell metal 
Phosphor bronze 
Solder 
Pewter 



Copper and aluminum 
Copper, zinc and nickel 
Copper, zinc, iron and manganese 
Copper and tin 
Copper and tin 
Copper, tin and phosphorus 
Tin and lead 

Tin, antimony, copper and bismuth 

Only a few of these alloys are used by the sheet metal worker. Sheet brass 

may take the place of cheaper materials for some work. Soft solder, made of 

tin and lead, or hard solders made of copper and zinc, are of great importance. 



Page Eight 



Shop Problems in Sheet Metal 



SOLDERING FLUXES. 

A flux is a material in any form, powder, paste or liquid, which helps to 
make the solder unite more easily with the metal. Most of these fluxes have 
some chemical action on the metals but some appear to do little but keep the 
solder flowing easily. 

A good flux for one kind of metal may not work well on others. For in- 
stance rosin will not work well on anything but bright tin. 

A list of the more commonly used fluxes follows: 

Rosin — either powdered or dissolved in gasoline or turpentine. Used for 
new work on tin plate. 

Zinc Chloride — made by cutting zinc with muriatic acid or by mixing the com- 
mercial zinc chloride with water. Used generally for all work. 

Raw Muriatic Acid — also called hydrochloric acid, generally diluted with 
water, sometimes mixed with the zinc chloride flux. Used for zinc, also for 
galvanized iron. 

Commercial soldering paste — containing various mixtures. Used for elec- 
trical work. 

Borax — in powdered or dissolved form, used for brass. 

RIVETING 

Sheet metal may be fastened together firmly by riveting and many times 
where strength is necessary both rivets and solder are used. The size of the 
rivets used depends both on the thickness of the metal and on the strength re- 
quired in the joint. 

The tinner usually sets his rivets by what is called "blind riveting." He 
places the rivet under the sheets of metal and draws it through by driving a 
rivet "set" over it with a hammer. This process requires some practice but 
makes a very firm joint because the rivet always fits the hole and may be drawn 
up very tightly. On some light work the rivet sometimes spreads out and 
stretches the metal around it. For this reason and because it is easier to place 
them accurately, rivets may be set in holes already punched in the sheets of 
metal. This is always done in heavy work. This process is recommended for be- 
ginners and the holes should be carefully located and punched with a solid punch 
over a block of wood on end grain. 

In heading a rivet a light hammer is used and light blows which form a head 
on the rivet slowly are necessary for good work. Use the rivet set to form a 
smooth head on the rivet. 

Tinners' rivets, which are usually coated with tin are sold by the box and 
are numbered 8 oz. or 10 or 12 or 14 oz., which means that 1,000 rivets of one 
size weigh a certain number of ounces. Larger rivets from 1 lb. up to 16 lbs. 
are sold, which are rated in pounds or per thousand. 



Page Nine 



Shop Problems in Sheet Metal 



HOW TO SOLDER, 

There are no secrets about the use of solder which may not be learned by 
the beginner, but the skill of the good mechanic does not come without many 
hours of practice. Thinking while you are working will shorten the learning 
of the process more than anything else you can do. 

Ordinary soft solder is an alloy of tin and lead, usually about half and half. 
It melts at about 350 degrees and unites easily with tin, lead, zinc, copper and 
brass, but not easily with iron or steel. 

There are four important principles to be remembered by any one who at- 
tempts to solder: — 

1. The soldering copper must be kept clean and well tinned. 

2. A good soldering flux must be used, and one which is suited to the metal. 

3. The metals to be soldered must be clean. 

4. The joint must be' heated above the melting point of the solder. 

Soldering requires heat. You may use gas, coal or charcoal or a gasoline 
torch to heat the coppers. If you use gas take care not to let the copper get 
smoked up in the yellow part of the flame. The blue flame is hotter, 

To try if the copper is hot enough you may touch it to a lump of solder, 
oi hold it near your face to test the heat. Do not overheat the copper or the 
tin will be burned off. 

When you are ready to solder a joint, see that the surfaces fit well and are 
clean. Apply the soldering flux to the joint with a small brush. Do not spread 
the flux over a wide surface. Touch the hot copper to the end of a bar of solder 
and then to the joint. See that only a narrow edge of the copper touches the 
joint. Try to have the solder flow along with the copper. Do not try to work 
fast as the heat must flow ahead of the solder and this takes time. Do not run 
back and forth over the joint but move in one direction. When the joint is 
soldered do not move it too soon but wait for the solder to set. Unnecessary 
solder may be wiped off with a cloth after heating a surface, but this should not 
be a common practice. 

Re-tinning the Copper. 

If for any reason the copper needs a new coat of tin you must remove 
the black surface with a file or grinding wheel. After you get it smooth heat 
it nearly to the point where it begins to show red. Rub on a soft brick or a 
block of sal-ammoniac to clean it and then pu^ a little solder on the block and 
work the tin into each of the four surfaces. This makes the point look bright 
and shiny like new tin. Your soldering copper must be kept in this condition 
to work well. 



Page Ten 



Shop Problems in Sheet Metal 



SHEET METAL PATTERN DRAFTING 
Sheet metal pattern drafting is mainly an application of the principles of 
developments and intersections as they are given in the usual courses in Me- 
chanical Drawing in high schools. In addition the sheet metal worker uses a 
great many short cuts, some of which are not strictly according to the rules of 
projection. But the pupil who lays out his patterns according to rule will not go 
wrong providing he makes proper allowances for seams, folds, wiring, etc. Since 
most of the articles made of sheet metal are in the form of cylinders, prisms, 
cones or pyramids, or parts of these solids, it will be well for the pupil who ex- 
pects to lay out his own patterns to study the forms of these solids and of their 
intersections with each other. So far as possible each pupil should learn to 
develop his patterns on paper and test them out in metal, but in order to save 
material the instructor should check all results with a master pattern. Since 
patterns made without proper allowances and without fixing the size, shape and 
location of notches are useless, particular attention must be paid to these details. 
Rules for these allowances are given in another paragraph. 

Allowances for Seams and Wiring. 

In an ordinary lock seam three times the width of the seam must be added 
to the edges before folding. Little attention is paid to the amount added on 
account of the thickness of the metal but where heavy metal is used this has to 
be considered. 

The allowance for wiring is usually twice the diameter of the wire plus 
twice the thickness of the metal, but experience in this case is a better guide 
than the rule, as it is hard to set the machines so that an exact amount will be 
turned on the edge of the material. 



Page Eleven 



Shop Problems in Sheet Metal 




Beakhorn Stake 




Hollow Mandrel Stake 




Conductor Stake 



Bio whom Stake 



fes.iWCo., 



r~ 



Candlemold Stake 



Double Seaming Stake 




Square Stake 





Creasing Stake 



Hatchet Stake 



Shop Problems in Sheet Metal 




Moores Double Seaming Machine 



Cornice Brake 





Groover 



Squaring Machine 




Folding Machine 



Shop Problems in Sheet Metal 




Setting Down Machine 



Turning Machine 



Wiring Machine 




Forming Machine 



Shop Problems in Sheet Metal 



SHEET METAL JO//VTS 



LAP JO /NT 

BSSBSaCBS 



^ffiS 3 



COUNTERSUNK 
JO /NT 




2SSESS3KSH5S 



BOX 
JO/NT 



BDSE-OVER JOINT OUTSfDE GROOVEO 

SEAM, 

ft/VETEO JO /NT 



tSTZZZZZEZZ 




CASN- 
aox 

JO/A/T 



2. 



/NStQE GROOVED essam^ 
OROO VEO JO/A/T SE/KM 



DOUBLE SEAMED 
BOTTOM 



2. 



3. 



INSTRUCTIONS AND OPERATIONS. 
Plate I. Sheet Metal Joints and Seams. 

Study these diagrams carefully. Learn the names of the joints and be able 

to describe each with a sketch. 

Note that the proportions of these joints and seams must vary somewhat 

with the thickness of the metal. Note also that they may need solder to 

hold the pieces together. 

Why is a grooved seam called a lock seam? What is the use of the hem and 

the double hem? 



Shop Problems in Sheet Metal 



FOLD//VG, Wm/NG AA/D R/VST/A/G 
EXERCISES 



SINGLE HEM 



FOl-DED SEAM 



DOUBLE HSM 



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5. 



Plate II. Exercises in Folding, Grooving and Wiring. 

(First Exercise.) 
Cut two pieces of scrap tin \y 2 by 8 inches in size. 

V/ith the folder set for a J/g inch sharp fold both edges of each piece. Care- 
fully flatten down one edge of each piece with a mallet on a flat surface. 
Hook the other two edges together and groove the seam with the proper 
grooving wheel on the machine. 
Fold one edge of this exercise over a second time to make a double hem. 

(Second Exercise.) 
Cut two pieces of galvanized iron 1% by 8 inches. 

Mark a line with the scriber % inch from the edge of each piece and lay 
off four points as indicated, marking the points with the prick punch. 
Punch these holes carefully using the machine or a solid punch on the end 
of a block of wood. 

Using 12 oz. tinned rivets fasten these pieces together carefully. Use a 
light riveting hammer and try to form a rounded head on the rivet. Finish 
the heads with a rivet set. 

Prepare the edges of this exercise for wiring by using the folder set to 3-16 
inch with the table set for an open fold. 

Cut two pieces of 14 guage wire eight inches long. Wire these in place 
as directed by the instructor. 



Shop Problems in Sheet Metal 



JP 



FOOT SCRAPERS. 




lb. RIVET 



9 „ 



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3=C 



CUT 





2. 



3. 



Plate III. Foot Scrapers. 

Choose one of these designs. Cut stock from black iron, 20 gauge or thick- 
er and 31/2 by 5 J/2 inches in size. 

Round all corners by marking with chalk and laying off a radius with di- 
viders. Cut and file to shape. 

Punch J/g inch holes for rivets on machine after carefully laying them off 
with steel rule. Bend pieces over a form in the cornice brake. Rivet with 
one-pound round head rivets. 
Punch holes for screws Yi inch from edge and fasten to doorstep. 



Shop Problems in Sheet Metal 



COOK/E CUTTER 




2t3 






j- 



■d*- Z #/6 Wire. 



± 



HANDLE 






BODY 



7? 






f 



>Ijj 



i 



Plate IV. Cookie Cutter. 

1. Cut stock of IC tin to dimensions given. 

2. Mark off allowances for wiring on larger piece, cut corner and wire with 16 
gauge wire. 

3. Run the body through the forming machine with the wired side down. 

4. Lap the ends just \/$ inch and hold with pliers while tacking with solder. 
Finish soldering after showing to the instructor. 

5. Prepare handle by wiring in the flat and forming in the machine. Crease 
ends in the stake or by using the turning machine. Solder in place after 
carefully fitting each end to the body. Remember that no joint should be 
soldered until the surfaces fit closely together at all points. 



Shop Problems in Sheet Metal 




Plate V. Match Safe. 

1. Cut three pieces to dimensions given. Scribe lines on edges |/g inch from 
edges and then ] /$ inch from these lines. Clip corners as indicated and lay 
off and cut design at the top. 

2. Fold double hem where marked. Bend three edges of each end in folder 
at right angles. Fold two long edges of main pattern J/g inch from edge 
and place J/g inch strip of scrap metal under each. 

3. Bend main pattern on first and second dotted lines. Remove strips of metal 
and slip ends in place. Double seam the ends over a stake or block of hard 
wood. Fold remaining edges toward the back with pliers. 



Shop Problems in Sheet Metal 



SUGAR SCOOP 



#/6 W/Ve 






^---- 



4% 



P-—~- 



HANOLE 



1 


1 


iK - 




1 1 

1 1 


•i i , i 


|! 




HAL 


F PATT£/?A 


r 




2. 



3. 



Plate VI. Sugar Scoop. 

This scoop is to be made of IC tin with back to be snapped on the body and 
soldered as indicated. The handle is to have wired edges. 
Use pattern to lay out body of scoop. Cut a piece for the back on the cir- 
cular shear and burr the edge J/g inch as indicated. 

Form the body to the required shape and snap inside of back. Tack care- 
fully in place with solder at several points, finally soldering |/g inch lap at 
the top. Solder back on the inside. Be careful not to overheat the joint at 
the lap. 

Wire the edges of handle. Form to shape in machine using your hands to 
bend the handle around the roll. Solder handle on the back after carefully 
fitting in place. 



Shop Problems in Sheet Metal 



rQUR P/£CEELBOW\ 

L 





Plate VII. Four Piece Elbow. 

Decide on the dimensions of the elbow wanted. Lay 
and string them together with strips of metal. Use 
given to lay out this set. Be sure to add to each 
for seams on all sides where necessary. 
Use the elbow edging roll and the burring machine 
tions. Slip parts in place and tack with solder. See 
twistsed before completing the soldering. 
Use a similar method if an elbow with three or five or 
The throat, OH, is about one-half the diameter of the 
creased. 



out a set of patterns 
the standard method 
pattern he alowances 

according to instruc- 
that the elbow is not 

more parts is wanted, 
pipe, but may be in- 



Shop Problems in Sheet Metal 



BR BAD PAN. 





i£/4 VV/RE 



*«*- 



6+' 




-H 



ft 



Plate VIII. Bread Tin. 

1. This pan is of the standard construction with equal tapering sides and solid 
corners. It may be made easier to construct by cutting away part of each 
corner. In this case the pan will not be water tight but will serve very well 
for a baking tin. 

2. If the solid pan is wanted, cut out the pattern as marked and form the cor- 
ners over a hatchet stake. Then turn the sides and ends over a block of 
hard wood cut just the shape of the inside of the pan. Use the hatchet 
stake and the mallet to close over the flaps but watch carefully to see that 
heavy blows are not used and that each corner is bent exactly on the lines. 
A pair of wide nosed pliers may be used to help turn the flaps. 

3. The wiring may be done by bending the edge of the sheet over the hatchet 
stake, and tucking the wire in place with the mallet and the wiring machine. 



Shop Problems in Sheet Metal 




Plate IX. Chick Feeder. 

1. Cut one piece of 30 guage galvanized stock thirteen and one-half inches 
square. Cut another piece six inches by eight inches for the front and one 
4% by 8J/8 inches for the lid. 

2. Lay off all these pieces according to the drawing and cut to size and shape. 

3. Fold main pattern to shape and rivet the bottom in place with 12 oz. rivets. 
One-half of the rivet holes may be punched before bending to position. 

4. Rivet the front in place on the dotted line shown in the drawing. 

5. Form the metal for the hinges and slip in a piece of No. 10 wire to form the 
hinge. 

6. Attach the lid after folding the edges at right angles. 



Shop Problems in Sheet Metal 



DUST PAN 



»oto 
A 



#ZO \A//f?£ 



\ 



1^ 



3' 




V ' J AMBLE 






GALVAMfZBO 0/? 3H££T 







CAP /=»/? 



Plate X. Dust Pan. 

1. Cut stock from 28 guage galvanized iron or from black stove pipe iron. Cut 
one piece 10J4 by 14 inches and one 5 by 5 inches. 

2. Lay off lines as indicated. Cut notches, clip corners and cut diagonal cuts 
for folding. Fold ]/$ inch hem on three sides. Run beading wheel over 
curved line to start bend. 

3. Turn edge for wiring setting folder ]4 inch. Fold corners and prepare wire 
for wiring. Bend wire in vise to get sharp bend \]/ 2 inches from each end. 
Wire the edge as directed by the instructor and solder the ends in place 
using acid flux. 

4. Prepare handle with lock seam and set in place through cuts marked in 
back as indicated. Hold handle firmly in place and turn flaps inward and 
solder down. If desired these flaps may be covered with a circular piece 
of metal soldered down. A narrow collar may also be soldered around the 
outside, where the handle joins the pan. A cap should be cut to fit the han- 
dle and soldered in place. 



Shop Problems in Sheet Metal 



CANTEEN 



Burr, 




MOTEr-THE W/DTHOft ]TH/5 BAND A/AY J Vl 
BE CHANGED TO SO/r\[ C 7 



l =r 



Z4-g 



Plate XL Canteen. 

1. Cut two sides on the circular shear and burr the edges J/g inch. Cut a band 
of tin of the desired width and fold both edges and flatten down in the brake 
with a ]/4 inch strip of 24 guage black iron under the edges. With the hollow 
chisel cut a semicircle from each end about one inch in diameter. 

2. Form the band into a circle on the former and remove the strips of iron 
carefully with a pair of pliers. Slip one of the sides carefully in place and 
tack with solder. Finish soldering and see that a very neat and smooth job 
is done. 

3. Slip second side in place and press out with a rod of wood introduced 
through the opening. See that it comes into place nicely before soldering as 
you did the first side. 

4. Cut three strips of scrap tin 7 /$ inch wide and fold a double hem in each edge. 
Bend these to the shape shown and solder in place on the outside as in the 
drawing. Solder on a screw cap taken from a can or purchased from a deal- 
er. 

5. The sides of this canteen may be padded and the outside covered with cloth 
or imitation leather if desired. 



Shop Problems in Sheet Metal 



P/MT TIN CUP 




WfR£ 



34- 




T~JL- 



L 






H 



PATTERN FO# BODY 



//-£ 



\ 



H 



>. 



1 




. 1 i 


us 


' 


f 


.i - 



m 






J 



Plate XII. One Pint Tin Cup. 

1. Cut three pieces of IC tin according to the dimensions given. 

2. Burr the edge of the bottom with the burring attachment on the circular 
shear. 

3. Prepare the ends of the long piece for a lock seam after carefully notching 
the corners. 

4. Wire the top edge of this piece with 14 guage wire. Form into a cylinder 
being careful not to spoil the fold for the seam. 

5. Finish the lock seam and solder on the inside. 

6. Burr the bottom edge on the burring machine and slip on the bottom. Turn 
the edge of the bottom carefully over the edge of the body with a hammer 
ana fasten with a setting down machine. If a double seaming machine is 
available it should be used at this point. If not, do the best you can with the 
mallet and the stake. 

7. Solder seam on the inside. 

8. Make the handle as you did the handle for the sugar scoop and solder it in 
place over the seam. 



Shop Problems in Sheet Metal 



^~)r 






"t 



QUART MEASURE 

SAL.V AfsJl 7LEO /&0A/ 



D/^METER OF 80YTOW 

5^r &Uf$R -£ 



L 



PATTe&Af FOR 
BODY 



XT 




^k_ 



■/*-£ -A 



I 



-V 



J 



Plate XIII. Quart Dry Measure. 

1. This measure may be made of 30 guage galvanized iron. It is calculated to 
hold 58 cubic inches. The instructions for making it are the same as for 
the tin cup, except for the handle. 



Shop Problems in Sheet Metal 



WATER PAIL 




Plate XIV. Water Pail. 

Cut two pieces just alike for the body of the pail. Double seam these to- 
gether on one edge and form to shape of pail and double seam again. Solder 
the inside of the seams carefully after grooving. 

Wire the top edge with No. 9 wire with the joint in the wire at one of the 
seams. 

Double seam the bottom as in other exercises, and solder inside. 
Rivet on two malleable ears and form a bail out of No. 6 wire and fasten in 
place. 
Note: — Other sizes of pails may be worked out in the same way. Use galvanized 
sheets not lighter than the 27 guage for a durable pail. 



Shop Problems in Sheet Metal 



rU/VA/EL 



PitLL'St* 




PATTERN FOR 
SPOUT 



1. 



2. 



5. 



Plate XV... Funnel. 

Lay out parts from patterns or make patterns from stiff paper in drawing 

room and submit to your teacher for inspection. Notice that the drawing 

gives the method generally followed in laying out any funnel pattern. 

Fold two straight edges of body in opposite directions and form to shape 

with your hands over a funnel stake. Groove the seam with a hand groover 

and solder inside. 

Turn the edge for wiring on the turning machine. Form the wire and fasten 

it in place with a mallet. Finish wiring on the machine. 

The spout may be made with a lap seam or with a lock seam. In either case 

it should be neatly soldered in place outside of the body of the funnel. 

Form the ring to shape with pliers and hammer, and solder clip in place 

just under the wire over the seam. 



Shop Problems in Sheet Metal 




2. 



3. 



Plate XVI. Gasoline Funnel. 

Follow instructions for small funnel except for top. Instead of wiring this 
edge make a band of metal one edge of which is wired in the flat. 
Form this band into a ring which is y& inch less in diameter than the di- 
ameter of the unfinished funnel. Solder the lock seam. 
Burr an edge on the band and with the elbow edging rolls turn a V shaped 
groove on the inside edge of the funnel and double seam. It should not 
be necessary to solder this joint. A second band may be made to slip inside 
this funnel to hold a piece of chamois skin in place, if desired. 



Sliop Problems in Sheet Metal 



U TIL I T Y MCA SURE 




Plate XVII. Utility Measure. 

1. This may be used as a measure and funnel combined or as common bottle 
filler. 

2. Cut the four pieces of stock as directed in the drawing. 

3. Form the body and solder the side seam on the inside. Wire the top edge 
and burr the bottom edge to receive the bottom. 

4. Double seam the bottom in place. Solder inside. 

5. Turn a hern on the curved edge of the hood with the burring machine and 
flatten with mallet. 

6. Form the hood to shape and solder the lap seam. Turn a groove in the edges 
which are to fit on the top edge of the measure with the small turner. Sol- 
der the hood in place beginning at the back and fitting the joint carefully. 

7. Solder the handle and the spout in place. The handle should fit over the 
seam. 



Shop Problems in Sheet Metal 



fishing tackle: box 



f= 




Corner of top 




Plate XVIII. Fishing Tackle Box. 
Cut stock for sides and ends in one piece, 4% by 26 9-16 inches. Lay off 
bends carefully with try square. Cut notches in lower edge and at corners. 
Turn a % inch hem at the top edge. Turn a loose hem in bottom edge and 
roll a bead just below the hem in the upper edge. This bead will stiffen the 
box and serve as a stop for the lid. 

Form a cash box joint in the ends and bend sides and ends to meet. Fit 
this joint neatly and solder inside. 

Make the top like a pan with corners folded over and fastened down on the 
outside and with a wired edge. 

Cut two pieces of tin for the hinges and after bending them around the 
wire slip through slits cut in the box just above the bead and solder down on 
on the inside. 
Design a clasp for the box and fasten in place. 



Shop Problems in Sheet Metal 



BREAD BOX 







Plate XIX. Bread Box. 

1. This box requires quite a large amount of material and should not be at- 
tempted by pupils who are careless. It should be made of good tin plate, 
heavier than that used for most exercises. When finished it may be enameled 
and nicely finished for use. » 

2. Cut the six pieces of stock as dimensioned. Allow for joints at all corners 
the amount marked. Also allow for wiring the edge of the cover. 

3. Turn all edges marked "A" at right angles, setting the folder at 3-16 inch. 
Turn all edges marked "B" all the way over with the same setting, but do 
not flatten down. Turn a double hem at the top. 

4. Fasten the front and back and ends together by double seaming. It will 
not be necessary to solder. 

5. Set the bottom in place and double seam over a square stake. 

6. The top is a simple pan with a wired edge which may be hinged in place in 
several ways. It should not fit too tightly. 

7. Handles may be soldered in place on the ends and a clasp may be designed 
and used to hold the lid in place. 



Shop Problems in Sheet Metal 




HEXAGONAL VASE 



3-d 'c£$' 



ro ^/rAr Pot NTS 
MARKEO B 




■MMHUHM 



2. 



3. 



4. 



5. 



Plate XX. Hexagonal Vase. 

This vase may be made of tin plate, galvanized iron or zinc. The pattern 
should first be worked out on paper and tested for accuracy. 
Cut six pieces from the standard pattern. Cut a template from scrap ma- 
terial which has an angle of 120 degrees. 

Begin bending the strips near the middle, using the cornice brake with 
curved wooden forms to secure the proper curvature. 

When all the parts have been bent as nearly the correct form as possible, 
begins soldering them together, using the template to test the interior angles 
Tack the parts at important intersections first and see that the vase does not 
get twisted in building it up. Great care should be taken to see that the 
strips are carefully fitted together before soldering. All the soldering can 
be done from the inside. 

A bottom and a false bottom can be soldered in place when the vase is com- 
pleted. 



LIBRARY OF CONGRESS 

■ML 

003 319 093 1 • 



